ME2 DLC

I haven't been able to find an answer, so I'm going to post the question. 

So the situation is: I have ME2 on my XBOX 360 and also paid for a bunch of DLC for it, such as Kasumi, Arrival, equipment, Shadowbroker, alternate appearances, etc. Unfortunately my XBOX 360 is dead, so wanting to play ME2 again, I bought and downloaded it from Steam. All well and good. I also got the Cerberus downloads. However, what I can't determine is how to get the rest of my DLC that I mentioned, that I've already paid for through XBOX. Is there a way to do this...or do I actually have to pay for all those things again? If that's the case, doesn't seem fair, but whatever. I just simply won't do it. Is there a way though? Thanks in advance for any help given.